Abstract

Holobenthic and merobenthic octopus ﬁsheries are commonly treated as biological equivalents, regardless of their contrasting life- history strategies. This is the consequence of a lack of species identiﬁcation and relevant biological information for many species, which has led to a reliance on catch per unit effort (cpue) data for stock status assessments. Using the commercial Octopus pallidus ﬁshery in southeast Australian waters as a case study, the reliability of commercial cpue data as an indicator of stock status for holo- benthic octopus ﬁsheries was assessed. To achieve this, cpue and biological information from a ﬁxed position experimental research line were investigated for consistency in stock status patterns and compared with commercial ﬁshery cpue trends. Research line results revealed that cpue could remain stable regardless of size-selective ﬁshing mortality potentially impacting recruitment. The cpue in the commercial ﬁshery was very seasonal and dominated by females during autumn, when both cpue and spawning periods peaked, so increasing the potential for negative ﬁshery impacts on egg production. The inability of cpue to account for the effects of continual ﬁshing pressure on recruitment or seasonal changes in sex-speciﬁc catchability, however, indicates that cpue alone cannot provide sufﬁcient information on the status of a holobenthic octopus ﬁshery.

Item Type:

Article

Keywords:

catch per unit effort, effects of fishing, octopus, recruitment, season